Increased performance of circuit devices including transistors, diodes, resistors, capacitors, and other passive and active electronic devices formed on a semiconductor substrate is typically a major factor considered during design, manufacture, and operation of those devices. For example, metal oxide semiconductor (MOS) transistor semiconductor transistor devices, such as those used in a complementary metal oxide semiconductor (CMOS), may operate or otherwise perform differently at temperatures higher than a nominal (25° C.) room temperature. Thus, devices designed for applications where higher than nominal temperature is possible may be designed with excess performance margin, so as to provide a desired albeit degraded level of performance under temperature.
The figures depict various embodiments of the present disclosure for purposes of illustration only. In the drawings, each identical or nearly identical component that is illustrated in various figures may be represented by a like numeral. For purposes of clarity, not every component may be labeled in every drawing. As will be appreciated, the figures are not necessarily drawn to scale or intended to limit the present disclosure to the specific configurations shown. For instance, while some figures generally indicate straight lines, right angles, and smooth surfaces, an actual implementation of a transistor structure may have less than perfect straight lines, right angles, and some features may have surface topology or otherwise be non-smooth, given real world limitations of the processing equipment and techniques used. In short, the figures are provided merely to show example structures. Numerous variations, configurations, and other embodiments will be apparent from the following detailed discussion.